Stereoscopic motion-picture projector



C. BOUIN STEREOSCOPIC MOTION PICTURE PROJECTOR Filed June 23, 1922 4 She ets-Sheet 1 ram c. BOUIN STEREOSCOPIC MOTION'PIGTURE PROJECTOR 4 She ets-Sheet 2 Filed June 23, 1922 WVEf/TUR: 6M fiw.

1,515,429 c. BOUlN STEREOSCOPIC MOTION PICTURE PROJECTOR Filed June 23 1922 4 Sheets-Sheet 5 Nov. 11, 924. 1,515,429

c. BOUIN STEREOSCOPIC MOTION PICTURE PROJECTOR Patented Nov. 11, 1924.

UNITED STATES PATENT OFFICE.

cnmrs Boom, or nosron, mssscnusnr'rs.

STEREOSCOPI C MOTION-PICTURE PROJECTOR;

Application filed June 28, 1922. Serial N0. 570,359.

the rays from such two images to a point of position upon a projection screen which superimposes the two images upon screen.

The invention relates more particularly to the method employed in a projection machine for causing an equal amount of convergence of both right and left images of a stereoscopic pair and also the method employed to adjust film in film' gate when images in film gate apertures are not in proper position, also the method employed to cause an equal amount of convergence of film gates and film images on film and maintaining the same relation of film images and film gate apertures in association with each other during process of convergence.

Further objects and advantages of the present invention will be pointed out in the hereinafter following description of one embodiment hereof, or will be obvious to those skilled in the mentioned arts.

Referring to the accompanying drawings:

Fig. 1 is a plan view showing method employed in converging difierent parts of projector, film, and method of adjusting film in film gate.

Fig. 2 is a plan view showing diflerent parts of projector and film in a position of greatest convergence.

Fig. 3 is a front elevation showing general constructioniof the front section of projector.

Fig. 4 is a rear elevation showing general construction of the 'rearsection of projector.

Fig. 5 is a side elevation of a left partition showing an opening through which film travels. 4 v

In Fi 1, H is a bearing which supports shutter jection lenses, the centre 0 shutter A being halfway between both lenses. Shutter A being revolved by means of gears 10 to 0. a to a, b to a, gear a and shutter A being on upon a shaft; A,1s-a shutter which is placed in front of the ri ht and left profilm Ohe revolution of gear 10 will revolve same shaft; B and B are left and right projection lenses; 7) and b are-racks and pin-.

ions; 6 are supports into which thumb screws 6 engage, shaft of thumb screw b rests andlens slides are attached; slides I) being between grooves b"; C and C are the two forward partitions supporting the left and right slides and lenses respectively; D

and D are the left and right partitions respectively, upon which the :left and right film gates are attached; F and F are left and right pressure plates, f and f are apertures in said pressure plates; G and G are left and right film gates, g and g are apertures in said film gates; ,h is a handle attached to gear 71 k meshing with gear 72/, gears hand h being attached to partitions D and B" respectively.

One revolution of crank shaft 13 will cause gears 11, 12, and 10 to revolve once, gear 10 in one revolution will revolve gear a four times, four revolutions of gear a. will revolve gear a eight times, gear I; revolving eight times will revolve gear'a and shutter A sixteen times. I

One rexgolution of crank shaft 13 will cause gear 10 to revolve gear 8 four times,

gears 8 and 9 being on same shaft, four revolutions of gear 9 will revolve gears 7 and 14 sixteen tlmes, gear 14 revolving sixteen times will engage and disengage the maltesecross 15 sixteen times, maltese-cross15 and gear 6 revolving of a circumference and resting sixteen times intermittently and gear 6 transmitting said motion to gear 5 and sprocket wheel 3; sprocket wheel 3 having sixteen teeth of standard distance apart and ofa revolution of such a sprocket wheel will advance film through film gate one image width of inch; in one revolution of crank shaft 13, sprocket wheel 3' will cause film to be intermittently advanced through film gate sixteen different periods of times a distance of inch at each of said periods.

through film gate may be varied. as desired by means of varying the size of gears .6, 5, or sprocket wheel 3.

One revolution of gear 10 will revolve ear 4 and sprocket wheel 2 four times, eeding film gate sixteen image widths of gear 4 and sprocket wheel 1 four times, takmg in film sixteen image widths of film length.

The distance of advancement offilm Considering the converging parts of rojector, on the left side, B is a projection lens which is mounted upon a slide 6, slide I) being between grooves 6 C is the forward partition supporting lens mechanism; D is the innermost partition supporting film gate G; in film gate G is an aperture 9; F is the pressure p ate and f is the'pressure plate aperture; 21 isan aperture in partition D through which film passes.

The converging parts on the right side of projector are the projection lens B which is mounted upon slide b, C is the forward pDartitiOn supporting lens and lens device;

is the innermost partition supporting film gate G which has an aperture g; F is the pressure plate which has an aperture f; 21 is an aperture in partition D through which fihn passes.

At the rear top ends of partitions D'and D a gear is permanently attached to each of tensions said partitions, gear it being at top rear of partition D, and gear h being at top rear of partition D- said two ears meshing and both gears being exact y the same size; gear 12. having a handle h permanently attached.

Between partitions D and D are two extensions, one of such extensions, 20, being attached to partition D and the second extension being attached to partition D; the opposite ends of extensions meeting and connected upon a rod midway between the partitions and D; said rod having a roller 19.

In Fig. 1, the projection lenses are shown in a parallel position in relation to each other and represents the point of greatest divergence and from such a parallel position of lenses convergence of the right and left projection lenses is accom lished by means of operating handle it; tlie relation of film in film gate and roller 19, and horizontal alinement of right and left film gates being as indicated in Fig. 1 when the projection lenses are in a parallel position.

At the innermost endof handle extension 18 is a roller 16 and on the inner half of handle extension is a thumb screw 17.

In Fig. 2, which is a plan view, the point of conver ence is shown at its greatest. Handle h aving been pushed forward and equally artly rotating gears h and k causes t e followin to be equally converged lens B and 1%, partitions C and C, partitions D and D, film gates G and G, pressure lates F and F, and the two ex- In the process of convergence the relation of the stereoscopic pairs of images on film to the film gate apertures g and g are maintained by means of roller 19; roller 19 being pushed backward by extensions 20 a distance sufiicient to correct the displace ment of images in film gate apertures which may have occurred in the process of conver ence.

o adjust film images in film gate apertures, handle 18 is pushed backward or forward, thereby increasing or decreasing the distance of len th of film between sprocket wheel 3 and film gate G; bringing handle in a backward direction will -cause roller 16 to advance forward and pressin against film will advance film through lm gate the desired distance; when the desired adjustment is obtained, thumb screw 17 is tightened to hold the position of roller 16 against film.

In Fig. 3, which is a front elevation, the lens operating. devices are shown. K is a casing in which gears are enclosed and 13 is the crank shaft; k and Marc rods supporting partitions; handle h turning gears h and b .will converge partitions D and D equally; the object of Fig. 3 is principally for showing the means employed to focus and raise or lower the projection lenses to the desired positions; I are grooves attached to partitions C and C b are slides laced between grooves 6 and B are eft and right projection lenses respectively which are mounted upon slides b; b are racks into which gears b engage, b is a thumb screw for rotatin gear I); b is a support for pinion gear s aft and slide 5;

I in support 6 thumb screw b engages.

The projection lenses are brought forward or backward in a focusing position by means of turning thumb screw b.

The projection lenses are raised or lowered to the desired positions by means of turning thumb screw 71 which engages support b In Fig. 4, which is a rear elevation, G is the left aperture plate and G is the right aperture plate; 9 is the aperture in left aperture plate, F is the left pressure plate and f is the aperture in left pressure plate, pressure plate is shown open and resting on top cover of casing K; F is the right pressure plate and f is the aperture in right pressure late, the pressure plate is shown closed. l he position of apertures as shown in Fig. 4 being suitable for images on film which are above and below horizontal centre 19 is the roller which has been described in Figs. 1 and 2.

In Fig.4, is shown a rear elevation of sprocket wheel 3 which advances film through film gate, and also is shown the film adjusting mechanism; 18 is the horizontal handle and 16 is the roller on the vertical part of handle extension; by means of handle 18 roller 16 advances film through film gate the desired degree of adjustment and after the desired adjustment is obtained proper relation to film' plate apertures hereequal convergence of corresponding parts of such a projector, or method of adjusting or maintaining the position of images in shown, butvarious other changes and modifications, within the skill of those versed in the mentioned arts may be made in such methods without departing from the spirit of my invention provided the principle set forth in the following claims be employed. Having thus described my invention, I claim? 1. In a stereoscopic motion picture projector, the combination of a pair of partitions, a projection lens on the forward end of each partition, a film gate on the rear end of each partition in line with therespect-ive lenses, a pressure plate for each film gate for maintaining a film thereacross, intermeslnng gears carried on the partitions to cause the simultaneous and equal divergenre and convergence of the partitions and elements carried thereby, a handle connected to one of the gears foroperating the same, a take up device connected to and arranged between the partitions for adjusting the film on the film gates to automatically maintain registry of the images of the film with the apertures of the film gates, drawing means for a film to pull it through the film gates and including a sprocket wheel, a handle, and a roller carried by the handle in posi- 'tion to engage the film between the gates and. the sprocket wheel for varying the length of film therebetween.

2; In a stereoscopic motlon picture proector, the combination of a pan of partilions, a projection lens on the forward end of each partition, a film gate on the rear end of each partition in line with the respective lenses, a pressure plate for, each film gate for maintaining-a fihn thereacross, inter-meshing ears carried on the partitions to cause the simultaneous and equal divergence and convergence of the partitions and elements carried thereby, a handle connected to one of the gears for operating the same, a take up device connected to and arranged between the partitions for adjusting. I

the film on the film gates to automatically maintain registry of the images of the film with the apertures of the fihn gates, a pair of pivotally connected links pivoted between the partitions and extending toward the path of the film, and a roller carried by the links at their pivoted connecting point and arranged to bear against the film when the partitions are moved toward each other for maintaining an equal length of film between the film gate at all-adjustments.

3. In a stereoscopic motion picture projector, the combination of a pair of partitions, a projection lens on the forward end" of each partition, a film gate on the rear end of each partition in hne with the respective lenses, a pressure plate for each film gate for maintaining a film thereacross, intermeshing gears carried on the partitions to cause the simultaneous and equal divergenceaud convergence of the partitions and elements carried thereby, a handle connected tc'one of the gears for operating the same, a take up device connected to and arrang'ed between the partitions for adjusting the film on the film gates to automatically maintain registry of the images of the film with the apertures of the film gates, drawing means for a film to pull it through the film gates and including a sprocket wheel, a handle, and a roller carried by the handle in position to engage the film between the gates and the sprocket wheel for varying the length of film therebetween, a pair of CHARLES BOUIN.

WVitnesses: i

MAY R. MoEvoY, MARGARET Pnanonr. 

